I do not believe that there is a one-click add to buddy list link for AIM. However, I do know that you can have your AIM status to the second, mobil, away, available, offline, idle, etc.
<a href="aim:goim?screenname=(screen-name)&message=Hello, Are You There?"><img border="0" src="http://api.oscar.aol.com/presence/icon?k=aw1qVADipZ5t2dh4&t=(screen-name)"/></a>
When you click on the status, it will bring open AIM and send the message.
Replace (screen-name) with the desired screen name.
Good Luck!
If you still need further assistance, feel free to contact me.
<a href="aim:goim?screenname=(screen-name)&message=Hello, Are You There?"><img border="0" src="http://api.oscar.aol.com/presence/icon?k=aw1qVADipZ5t2dh4&t=(screen-name)"/></a>
When you click on the status, it will bring open AIM and send the message.
Replace (screen-name) with the desired screen name.
Good Luck!
If you still need further assistance, feel free to contact me.